This invention relates to mechanical speed reducing devices of the type employing a nutator member which has imparted to it a nutating movement by a drive shaft, such member being cooperable with toothed rotary members one stationary and the other turnable, to effect a transmission and reduction in speed.
Various types of speed-reducing devices of the above nature have been proposed and produced in the past. One drawback of such devices has resided in the nutating nature of the movement imparted by the input or drive shaft to the nutator. This has resulted in considerable stresses and vibration, and has severely limited the upper limit of operating speeds of the mechanisms and also placed limitations on the sizes of the components, involving requirements as to minimum size, weight, etc. Another drawback of prior nutator-type speed reducers has involved the extreme accuracy that was required in forming or machining the cooperable parts, particularly the nutator member and the rotary members engageable therewith. Slight variations of dimensions resulted in looseness, lost motion, hammering and excessive wear. Still another drawback of prior speed reducers of the type indicated resulted in the fact that the ratio of the input to the output speed was fixed for any given mechanism, and could not be conveniently altered to enable a selection of different speeds or ratios to be had.